Vacuum interrupter, manufacturing method of vacuum interrupter

Abstract

A technology is provided that can contribute to making it easier to braze both the coil portion and the reinforcing portion and to making it easier to obtain desired electrode characteristics. [Solution] A reinforcing part 6 having a cylindrical peripheral wall 60 with a smaller diameter than the coil part 3 is provided concentrically on the inner peripheral side of a cylindrical coil part 3. The coil part 3 has a first slit hole 31 and a second slit hole 32 formed at a predetermined interval in the circumferential direction, the first slit hole 31 penetrating the coil part 3 in the radial direction and extending in the axial direction. The reinforcing part 6 has a surface joint part 61 that is surface-joined to the inner peripheral surface 30a of the coil part 3, and an annular groove part 62 that extends in the circumferential direction in the surface joint part 61. The groove part 62 is shaped so that it is open only on the side facing the inner peripheral surface 30a. The surface joint part 61 is brazed to the inner peripheral surface 30a via a brazing material 7 provided in the groove part 62.

Description

[Technical field]

[0001] The present invention relates to a vacuum interrupter and a manufacturing method for a vacuum interrupter, and relates to a technique applicable to, for example, various electric power facilities and the like. [Background technology]

[0002] For example, one example of a vacuum interrupter applied to various electric power facilities and the like is configured such that a pair of electrodes (a fixed electrode and a movable electrode) are provided in a vacuum vessel having an insulating cylindrical body, facing each other (hereinafter, the facing direction will be referred to simply as the facing direction) in the axial direction of the cylindrical body (hereinafter, appropriately referred to as the axial direction) and can be moved toward and away from each other. A pair of current-carrying shafts (leads) are provided in the vacuum vessel so as to support the back sides (opposite the facing direction) of each electrode. One of the current-carrying shafts (for example, the movable current-carrying shaft 12b described below) is supported inside the vacuum vessel via a bellows that is expandable and contractible in the axial direction.

[0003] With a vacuum interrupter configured as described above, one of the current-carrying shafts (the movable current-carrying shaft) can be moved axially while maintaining a vacuum state inside the vacuum vessel (specifically, on the outer periphery of the bellows inside the vacuum vessel). This makes it possible to connect and disconnect the electrodes in response to the movement of the current-carrying shaft, thereby opening and closing the contacts.

[0004] It is common for each electrode to be configured to have a magnetic field generating function in order to facilitate the achievement of desired breaking performance, etc. One example of this configuration includes a cylindrical coil section (magnetic field generating coil section) extending in the axial direction, a contact section provided on the opposing side (contact side) of the coil section, and an adapter section that supports the back side (opposite side of the opposing direction) of the coil section on a current-carrying shaft.

[0005] When the electrodes of such a configuration are brought into contact with each other to open and close the contacts, stress (for example, inertial force in the axial direction or mechanical impact force, etc.) may be applied to the electrodes. In addition, since the coil section is provided with multiple slits to generate a magnetic field, the mechanical strength of the electrodes may be easily reduced, and it may be impossible to obtain the desired electrode characteristics (mechanical characteristics, electrical characteristics, etc.).

[0006] For this reason, studies have been conducted to provide a cylindrical reinforcing portion concentrically on the inner periphery of the coil portion so as to be able to withstand the above-mentioned stress and to obtain the desired electrode characteristics.

[0007] Patent Documents 1 to 3 disclose an embodiment in which each component of an electrode (coil portion, contact portion, adapter portion, reinforcing portion, etc.; hereinafter, simply referred to as electrode elements) is assembled by brazing. In this brazing, for example, when the electrode elements are first assembled to form a desired electrode shape, a brazing material is placed between each assembly surface (or in the vicinity of each assembly surface) of two adjacent electrode elements (two electrode elements brazed to each other). Then, the assembled assembly is heated or the like to melt the brazing material, and the molten brazing material is allowed to permeate between the assembly surfaces (for example, permeate so as to spread widely by capillary action) and then solidified (solidified by lowering the temperature). This makes it possible to braze each assembly surface.

[0008] In the brazing methods disclosed in Patent Documents 1 to 3, the placement of the brazing material is not disclosed, but it is possible to consider how to avoid impairing the assembly and installation of each electrode element. For example, the reinforcing part is assembled (e.g., assembled by fitting) so as to be concentrically positioned on the inner periphery side of the coil part, so it is desirable to ensure that this assembly is not hindered.

[0009] In this case, for both the coil portion and the reinforcing portion, after assembling the two, they may be brazed to each other (for example, in Patent Document 3, brazing to the contact portion indicated by reference symbol 4 and the adapter portion indicated by reference symbol 6) via brazing material arranged at locations other than between the two (for example, in Patent Document 3, the end faces indicated by reference symbols 1a, 1b, 5a, and 5b). [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2010-267442 A [Patent Document 2] JP 2013-041735 A [Patent Document 3] JP 2018-181681 A Summary of the Invention [Problem to be solved by the invention]

[0011] It is also desirable to assemble both the coil portion and the reinforcing portion to each other by brazing, etc. However, with a brazing material disposed in a location other than between the coil portion and the reinforcing portion as described above, even if it melts, it is difficult for the brazing material to penetrate between the two (between the respective assembly surfaces), and sufficient brazing cannot be achieved, which may result in failure to obtain desired electrode characteristics.

[0012] The present invention has been made in consideration of such technical problems, and aims to provide a technology that can contribute to making it easier to braze both the coil portion and the reinforcing portion and to making it easier to obtain desired electrode characteristics. [Means for solving the problem]

[0013] The vacuum interrupter and the manufacturing method for the vacuum interrupter according to the present invention can contribute to solving the above problems.

[0014] First, one embodiment of a vacuum interrupter comprises a vacuum vessel having an insulating cylindrical body, a pair of electrodes disposed within the vacuum vessel facing each other in the axial direction of the cylindrical body and capable of moving toward and away from each other, and a pair of conductive shafts supporting each of the electrodes on opposite sides of the facing direction.

[0015] Each electrode has a cylindrical coil portion extending in the axial direction, a contact portion provided at an opening in the coil portion in the opposing direction, an adapter portion provided on the opposite side of the coil portion in the opposing direction and supported by the current-carrying shaft, and a reinforcing portion that is cylindrical and has a smaller diameter than the coil portion and is concentrically arranged on the inner side of the coil portion.

[0016] The coil portion has a plurality of slit holes formed at predetermined intervals in the circumferential direction of the coil portion, the slit holes passing through the coil portion in the radial direction and extending in the axial direction.

[0017] The reinforcing portion has a surface-jointed portion that is surface-joined on the outer peripheral surface of the reinforcing portion to the inner peripheral surface of the coil portion, and an annular groove portion that extends in the circumferential direction at the surface-jointed portion.

[0018] The groove portion is open only on the side facing the inner circumferential surface of the coil portion.

[0019] The surface joint portion is brazed to the inner circumferential surface of the coil portion via a brazing material provided in the groove portion.

[0020] The surface joint portion may be annular in shape and have a diameter that expands radially outward from an outer circumferential surface of the reinforcing portion.

[0021] The brazing material may be a filament extending along the groove, and one or more filaments may be provided for each groove.

[0022] In addition, when the number of stages of the filament provided in the groove in the axial direction is N, the number of stages of the filament provided in the groove in the radial direction is S, the wire diameter of the filament is φ, the dimension of the groove in the axial direction is w1, and the dimension of the groove in the radial direction is w2, the following formulas (1) and (2) may be satisfied. φN <w1<φ(N+1) …(1) φS <w2<φ(S+1) …(2)。

[0023] The filament may also be characterized in that a cutout portion having a shape penetrating in the axial direction is formed in a part of the circumferential direction, and the cutout portion is elastically deformable so as to expand and contract in the circumferential direction.

[0024] One aspect of the manufacturing method of the vacuum interrupter includes a brazing material disposing step of disposing the brazing material in the groove portion, and a reinforcing portion assembling step of providing the reinforcing portion on an inner circumferential side of the coil portion, and a melting step of heating and melting the brazing material. Effect of the Invention

[0025] As described above, according to the present invention, it is possible to easily braze both the coil portion and the reinforcing portion, thereby contributing to making it easier to obtain desired electrode characteristics. [Brief description of the drawings]

[0026] [Figure 1] 1 is a schematic diagram (axial longitudinal sectional view) illustrating a schematic configuration of a vacuum interrupter 1A according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram (appearance diagram) for explaining a schematic configuration of an electrode 2 (a fixed electrode 2a and a movable electrode 2b). [Diagram 3] FIG. 2 is a schematic diagram (longitudinal cross-sectional view in the axial direction) illustrating a schematic configuration of an electrode 2 (a fixed electrode 2a and a movable electrode 2b). [Figure 4] FIG. 2 is a schematic diagram (appearance diagram) illustrating a schematic configuration of a coil portion 3. [Diagram 5] FIG. 2 is a schematic diagram (appearance diagram) illustrating a schematic configuration of a contact portion 4. [Figure 6] 1A and 1B are schematic diagrams illustrating the schematic configuration of a reinforcing portion 6 ((A) shows the case where one piece of brazing material 7 is used, and (B) shows the case where two pieces of brazing material 7 are used). [Figure 7] Schematic diagram showing the observation results of a verification example ((A) is for electrode 2, and (B) is for electrode 9). [Figure 8] FIG. 1 is a schematic diagram (longitudinal cross-sectional view) illustrating a conventional configuration. [Figure 9] FIG. 13 is a schematic diagram (appearance diagram) illustrating a reinforcing portion 91 of a conventional configuration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The vacuum interrupter and the manufacturing method of the vacuum interrupter according to the embodiment of the present invention are completely different from a configuration in which the coil portion and the reinforcing portion are simply soldered together via solder material placed at a location other than between the two (hereinafter referred to as simply the conventional configuration).

[0028] That is, this embodiment has a configuration having a surface-joining portion that is surface-joined on the outer peripheral surface of the reinforcing portion to the inner peripheral surface of the coil portion, and a ring-shaped groove portion that extends in the circumferential direction of the coil portion (hereinafter simply referred to as the circumferential direction) in the surface-joining portion and in which a brazing material can be provided. The groove portion is shaped so that it is open only on the side facing the inner peripheral surface of the coil portion. The surface-joining portion of the reinforcing portion is brazed to the inner peripheral surface of the coil portion via the brazing material provided in the groove portion as described above.

[0029] According to the configuration of this embodiment, it is possible to assemble the coil portion and the reinforcing portion by brazing them together so that the assembly of the reinforcing portion to the inner periphery side of the coil portion is not hindered.

[0030] 8 and 9 described later, in the case where a notched groove 93 for placing the brazing material 7 is provided on the outer peripheral edge of the open end face 92 of the reinforcing part 91 on the adapter part 5 side, there is a possibility that the brazing material 7 placed in the notched groove 93 can melt and penetrate between the assembly surfaces (between the inner peripheral surface 30a and the outer peripheral surface 60a) of the coil part 3 and the reinforcing part 91. However, since the notched groove 93 as described above has a shape that opens on the adapter part 5 side, it is conceivable that most of the molten brazing material 7 will flow to the adapter part 5 side (for example, flow along the assembly surface of the adapter part 5), and there is a risk that both the coil part 3 and the reinforcing part 91 cannot be brazed.

[0031] On the other hand, in the configuration of this embodiment, the groove portion provided in the surface joint of the reinforcing part is open only on the side facing the inner surface of the coil part, so that the molten solder material in the groove portion can be prevented from flowing toward the adapter part (for example, flowing along the assembly surface of the adapter part).

[0032] This makes it easier for the brazing material molten in the groove to permeate between the assembly surfaces of the coil portion and the reinforcing portion (for example, to permeate widely by capillary action), which means that it becomes easier to braze the coil portion and the reinforcing portion together, and this can also contribute to the electrode characteristics.

[0033] As described above, this embodiment has a configuration in which a groove portion having a shape that is open only on the side facing the inner peripheral surface is provided in a surface-joint portion of the outer peripheral surface of the reinforcing portion that is surface-joined to the inner peripheral surface of the coil portion, and the reinforcing portion and the coil portion are brazed via the brazing material provided in the groove portion. Therefore, it is possible to appropriately apply technical common sense in various fields (vacuum interrupter field, electrode field, brazing field, etc.) and appropriately refer to prior art documents as necessary to modify the design, and the following example is one example of such a configuration.

[0034] In the following examples, detailed description will be omitted as appropriate by, for example, referring to the same reference numerals to similar contents. Also, in Fig. 7 described later, the fillet 70 made of the brazing material 7 is depicted in an exaggerated manner for convenience.

[0035] Example <Main configuration examples of vacuum interrupters> An example of the schematic configuration of a vacuum interrupter 1A according to an embodiment will be described with reference to Fig. 1. This vacuum interrupter 1A includes a vacuum vessel 1 having an insulating cylindrical body 10, one axial side (fixed side) of which is sealed by a fixed side flange 1a, and the other axial side (movable side) of which is sealed by a movable side flange 1b.

[0036] In the case of the cylindrical main body 10 shown in Figure 1, a cylindrical shield (arc shield) 11 surrounding the outer circumferential sides of a fixed electrode 2a and a movable electrode 2b described below is supported on the inner circumferential side of the cylindrical main body 10.

[0037] A columnar fixed-side current-carrying shaft 12a is provided at the center of the fixed-side flange 1a so as to extend from the center to the other side in the axial direction (extending from one side in the axial direction to the other side in FIG. 1). A fixed electrode 2a is supported at the end of the fixed-side current-carrying shaft 12a on the other side in the axial direction.

[0038] A flange through hole 13 is provided in the center of the movable side flange 1b, passing through the center in the axial direction, and a columnar movable side current-carrying shaft 12b is inserted into the flange through hole 13 and extends in the axial direction.

[0039] The movable electrode 2b is supported at one axial end of the movable current-carrying shaft 12b. The one axial end of the movable current-carrying shaft 12b (the movable electrode 2b side) is supported inside the vacuum vessel 1 of the movable flange 1b via a cylindrical bellows 14 that is expandable and contractable in the axial direction and is arranged coaxially with the movable current-carrying shaft 12b.

[0040] The fixed electrode 2a and the movable electrode 2b are provided with slits and the like (specific examples include a first slit hole 31, a second slit hole 32, a slit groove 36, and a contact-side slit hole 41, which will be described later) so as to have a magnetic field generating function.

[0041] According to the vacuum interrupter 1A configured as described above, the movable side current-carrying shaft 12b (and the movable electrode 2b) can be moved in the axial direction while maintaining the vacuum state inside the vacuum vessel 1 (specifically, on the outer periphery of the bellows 14 inside the vacuum vessel 1), and the movable electrode 2b can be moved toward and away from the fixed electrode 2a in accordance with the movement of the movable side current-carrying shaft 12b.

[0042] The materials, shapes, etc. of each component of vacuum interrupter 1A, as well as the processing methods, assembly methods, and installation methods of each component, can be appropriately applied in various aspects depending on the intended use of vacuum interrupter 1A, etc.

[0043] For example, among the components of the vacuum interrupter 1A, an insulating material (e.g., alumina ceramics) can be used for the cylindrical body 10, and a metallic material (e.g., stainless steel (SUS304), oxygen-free copper, titanium) can be used for the others. However, it is preferable to select the appropriate material taking into account that expansion (thermal expansion) and residual stress may occur when assembling the components.

[0044] <Main configuration examples of the fixed electrode 2a and the movable electrode 2b> The fixed electrode 2a and the movable electrode 2b are configured to have a magnetic field generating function for the purpose of making it easier to exhibit the desired blocking performance, and it is sufficient that the coil portion 3 and the reinforcing portion 6, which will be described later, among the electrode elements of the electrode 2 are brazed together, and examples of the configurations shown in Figures 1 to 6 can be mentioned.

[0045] The fixed electrode 2a and the movable electrode 2b may have the same configuration, and hereinafter, as necessary, they will be collectively referred to simply as the electrode 2. Furthermore, hereinafter, the fixed-side current-carrying shaft 12a and the movable-side current-carrying shaft 12b will be collectively referred to simply as the current-carrying shaft 12 as necessary.

[0046] 1 to 6 includes a coil section (magnetic field generating coil section) 3 having a cylindrical peripheral wall 30 extending in the axial direction, a disk-shaped contact section 4 provided on an open end face 33 on the opposing side (contact side) of the coil section 3, and a disk-shaped adapter section 5 supporting an open end face 34 on the back side (opposite the opposing direction) of the coil section 3 on a current-carrying shaft 12. A reinforcing section 6 having a cylindrical peripheral wall 60 with a smaller diameter than the coil section 3 is fitted concentrically around the inner periphery of the coil section 3.

[0047] The material, shape, etc. of each electrode element of the electrode 2, as well as the processing method, assembly method, installation method, etc. of each electrode element can be appropriately applied in various modes according to the intended use of the vacuum interrupter 1A. For example, it is preferable to use a metal material with high conductivity for the coil portion 3, the contact portion 4, and the adapter portion 5, such as oxygen-free copper. On the other hand, it is preferable to use a metal material with high mechanical strength for the reinforcing portion 6, such as stainless steel (SUS304).

[0048] <Configuration example of coil section 3> The coil portion 3 has a first slit hole 31 which penetrates the peripheral wall 30 in the radial direction (hereinafter simply referred to as the radial direction) of the coil portion 3 and extends in the axial direction (in the figure, a shape extending along the axis 35 in the so-called Z-winding direction) and opens to the opening end face 33 side, and a second slit hole 32 which penetrates the peripheral wall 30 in the radial direction (hereinafter simply referred to as the radial direction) of the coil portion 3 and extends in the axial direction like the first slit hole 31 and opens to the opening end face 34 side, and these are alternately formed at a predetermined interval in the circumferential direction of the coil portion 3 (six of each in the figure).

[0049] A slit groove 36 is formed at the opening end surface 33 on the opening side of each of the first slit holes 31, and has a shape penetrating therethrough in the radial direction.

[0050] The first slit hole 31, the second slit hole 32, and the slit groove 36 may be formed in various ways so long as they are capable of generating a desired magnetic field. In the case of the first slit hole 31 and the second slit hole 32 in the figure, they are shaped to extend from the vicinity of the center in the axial direction of the coil section 3 to the respective opening sides (opening end faces 33, 34 sides) and are shaped to be inclined at an angle (inclination angle) α with respect to the axial center 35 of the coil section 3, but are not limited thereto.

[0051] The angle α can be set appropriately, and an example of the angle is within a range of 60° to 80°. The circumferential opening angles of the first slit holes 31, the second slit holes 32, and the slit grooves 36 with respect to the axis 35 of the coil portion 3 can also be set appropriately (for example, set to a constant value), and an example of the angle is within a range of [540 / s]° to [1440 / s]° (s is the total number of the first slit holes 31, the second slit holes 32, and the slit grooves 36).

[0052] In the case of the coil portion 3 in the figure, a surface-bonded portion 30b having a shape that is reduced in diameter inward in the radial direction is formed on the adapter portion 5 side of the inner circumferential surface 30a (a portion facing a surface-bonded portion 61 described later in the figure). This makes it easy for the surface-bonded portion 30b of the inner circumferential surface 30a of the coil portion 3 to be surface-bonded to the outer circumferential surface 60a of the reinforcing portion 6.

[0053] <Configuration example of contact part 4> The contact portion 4 can be configured to obtain a desired magnetic field generating function, similar to the coil portion 3. As a specific example, there can be mentioned a mode in which a plurality of contact side slit holes 41 are formed at predetermined intervals in the circumferential direction of the contact portion 4, each of which has a shape penetrating the thickness direction (axial direction) of the contact portion 4 and extending in the radial direction and opening to the outside in the radial direction (toward the outer circumferential end face 40).

[0054] In the case of each contact-side slit hole 41 in the figure, the radially inner end 42 of the contact-side slit hole 41 is located away from the axis 35, and as it approaches the radially outer side, it is inclined so as to be biased from the radial direction to one side in the circumferential direction (the clockwise direction when viewed from the opposing side in the figure). Each contact-side slit hole 41 of such a shape forms a spiral shape as a whole, as shown in FIG.

[0055] In addition, the contact portion 4 in the figure is formed with the same number of contact side slit holes 41 as the slit grooves 36, and is provided on the opening end surface 33 of the coil portion 3 so that the outer peripheral end surface 40 side (opening side) of the contact side slit holes 41 is positioned opposite the slit grooves 36. This results in a configuration in which the first slit holes 31 and the contact side slit holes 41 communicate with each other via the slit grooves 36.

[0056] <Configuration example of adapter unit 5> The adapter part 5 may be configured in various ways as long as it can support the open end face 34 on the back side (opposite side in the facing direction) of the coil part 3 on the current-carrying shaft 12. For example, in the case of the adapter part 5 in the figure, the center part of the adapter part 5 is configured to be supported by the current-carrying shaft 12.

[0057] In addition, in the case of the adapter part 5 in the figure, it is configured separately from the coil part 3, but this is not limited thereto, and it may be configured integrally with the coil part 3. In this case, the coil part 3 and the adapter part 5 form a bottomed cylindrical structure as a whole.

[0058] <Configuration example of reinforcing portion 6> The reinforcing portion 6 has a surface-bonding portion 61 formed on an outer peripheral surface 60a of the peripheral wall 60, which is surface-bonded to the inner peripheral surface 30a of the coil portion 3. In addition, an annular groove portion 62 extending in the circumferential direction is formed in the central portion in the axial direction of the surface-bonding portion 61, and the groove portion 62 is configured to be able to accommodate the brazing material 7.

[0059] Various configurations are possible for the surface-bonding portion 61, as long as it can be surface-bonded to the inner circumferential surface 30a with the reinforcing portion 6 provided on the inner circumferential side of the coil portion 3. In the case of the reinforcing portion 6 shown in the figure, a ring-shaped surface-bonding portion 61 that expands radially outward is formed at a location on the outer circumferential surface 60a of the peripheral wall 60 facing the surface-bonded portion 30b on the adapter portion 5 side, and the surface-bonding portion 61 is configured to be easily surface-bonded to the surface-bonded portion 30b, but is not limited to this.

[0060] For example, the surface-to-be-bonded portion 30b and the surface-to-be-bonded portion 61 in the figure are formed facing each other only in a portion of the axial direction of the inner surface 30a and the outer surface 60a, respectively (the area on the adapter portion 5 side in the figure), but they may be formed over the entire axial direction, or may be formed only in the central area in the axial direction or the area on the contact portion 4 side.

[0061] The groove portion 62 is open only on the side facing the inner circumferential surface 30a of the coil portion 3, and the radially inner side and axial side of the groove portion 62 are sealed by a groove inner wall surface 63.

[0062] As described above, the groove 62 is open only on the side facing the inner circumferential surface 30a of the coil portion 3, and various configurations are possible as long as the desired brazing material 7 can be placed therein. In the case of the groove 62 shown in the drawing, the cross-sectional shape of the groove inner wall surface 63 in the axial direction is U-shaped, but it may be other shapes such as a U-shape or a V-shape.

[0063] <Example of composition of brazing material 7> The brazing material 7 can be provided so as to extend circumferentially relative to the groove portion 62 so as not to interfere with the assembly of the reinforcing portion 6 to the inner periphery of the coil portion 3. Any material can be used as long as it is capable of brazing the coil portion 3 and the reinforcing portion 6 when the brazing material 7 provided in the groove portion 62 is melted and then solidified, and various embodiments can be applied.

[0064] For example, when the coil portion 3 is made of oxygen-free copper and the reinforcing portion 6 is made of stainless steel, the brazing material 7 may have a melting point lower than that of the oxygen-free copper. One example of the brazing material is an Ag-based material (such as Ag-Cu-based material).

[0065] Furthermore, for example, when a long linear brazing material product that can be plastically deformed by bending or the like is used as the brazing material 7, the brazing material product may be formed into a molded body (hereinafter simply referred to as a filament) having a shape extending along the groove 62. Specific examples include applying a filament obtained by winding the brazing material product along the groove 62 (for example, winding the brazing material product around the groove 62 by one revolution or less), or fitting a filament obtained by previously molding the brazing material product into the groove 62.

[0066] The filamentary brazing material 7 may be provided in a single piece (one row in the axial direction) as shown in FIG. 6(A), or in a plurality of pieces (two rows in the axial direction in FIG. 6(B)).

[0067] Also, the brazing material product may be wound in a spiral shape along the groove 62 (a predetermined number of turns), thereby forming the spiral filament. When forming such a spiral filament, the number of stages in the axial direction of the filament increases by one stage each time one turn is wound around the groove 62 and the next turn begins.

[0068] Also, the brazing material product may be wound in a spiral shape around the groove 62 (a predetermined number of turns), thereby forming the spiral filament. When forming such a spiral filament, the number of radial stages of the filament increases by one each time one turn is wound around the groove 62 and the next turn begins.

[0069] When using the brazing material 7 made of the filaments as described above, it is possible to appropriately design it so as to satisfy the following formulas (1) and (2). Here, the number of axial rows of the filaments provided in the grooves 62 is N, the number of radial rows of the filaments provided in the grooves 62 is S, the wire diameter of the filaments is φ, the groove width dimension (axial dimension) of the grooves 62 is w1, and the depth dimension (radial dimension) of the grooves 62 is w2. φN <w1<φ(N+1) …(1) φS <w2<φ(S+1) …(2)。

[0070] By appropriately designing to satisfy these formulas (1) and (2), the entire brazing material 7 of the filament can be easily accommodated in the groove 62, and assembly of the reinforcing part 6 to the inner periphery side of the coil part 3 can be prevented from being hindered. Also, a suitable surplus space 64 can be provided between the brazing material 7 provided in the groove 62 and the groove inner wall surface 63. In this case, it may be easier to arrange the brazing material 7 in the groove 62.

[0071] The brazing material 7 may have a structure having appropriate elasticity (elasticity that does not cause plastic deformation), which allows it to be fitted in a snap-fit ​​manner into the groove portion 62. Specifically, in the case of the brazing material 7 in the figure, a cutout portion 71 having a shape penetrating in the axial direction is formed in a part of the circumferential direction of the brazing material 7.

[0072] In the case of such brazing material 7, the cutout portion 71 is elastically deformed so as to expand in the circumferential direction to expand its diameter, and then the brazing material 7 is arranged concentrically with the outer periphery of the groove portion 62, and then the brazing material 7 is elastically restored, so that the brazing material 7 can be fitted into the groove portion 62. In addition, the brazing material 7 can be prevented from coming off the groove portion 62, for example.

[0073] When a plurality of brazing materials 7 having cutout portions 71 are provided, it is preferable to appropriately set the cutout portions 71 of the brazing materials 7 so that they do not overlap in the axial direction. For example, in the case of the cutout portions 71 of the two brazing materials 7 in Fig. 6(B), they can be set to be positioned opposite each other in the radial direction (for example, to be positioned at the front side and the back side in Fig. 6(B)).

[0074] When the brazing filler material 7 made of the filaments cannot be positioned in the groove 62 as desired, for example, a part of the brazing filler material 7 may protrude outward from the opening of the groove 62 (hereinafter, simply referred to as a protruding state). Such a protruding state of the brazing filler material 7 can be recognized, for example, when the inner circumferential surface 30a or the opening end surface 33 of the coil portion 3 collides with the protruding portion of the brazing filler material 7 while an operator is assembling the reinforcing portion 6 to the inner circumferential side of the coil portion 3.

[0075] If a protruding state of the solder material 7 is recognized, the assembly work can be stopped and the cause of the protruding state can be eliminated (for example, by correcting distortion or replacing the filament, changing the number of axial or radial stages of the filament, or reviewing the assembly work), and then the assembly work can be performed again.

[0076] Furthermore, if the solder material 7 is elastic as described above or if excess space 64 is formed, even if the inner surface 30a or the opening end face 33 of the coil portion 3 collides with the protruding portion of the solder material 7 during assembly, it may be possible to continue the assembly work by pushing it in while applying additional pressure as appropriate, and there is a good chance that the entire solder material 7 will be contained within the groove portion 62.

[0077] <An example of how to assemble each electrode element> Each electrode element of the electrode 2 can be assembled using appropriate soldering material, but the assembly of the reinforcing portion 6 to the inner periphery of the coil portion 3 can be performed in the following order: soldering material placement process, assembly process, and melting process.

[0078] First, in the brazing material placement step, brazing material 7 is provided in groove portion 62 of reinforcing portion 6, for example, as shown in Fig. 6. Then, in the assembly step, reinforcing portion 6 is fitted concentrically to the inner periphery of coil portion 3, thereby assembling coil portion 3 and reinforcing portion 6, for example, as shown in Fig. 3, to obtain an assembly in which surface-bonding portion 61 and surface-bonded portion 30b are surface-bonded.

[0079] Next, in a melting step, the brazing material 7 is heated to a molten state, for example, by placing the assembly in a heating furnace. The brazing material 7 in this molten state permeates widely between the surface-to-surface joining portion 61 and the surface-to-be-joined portion 30b (between the respective assembly surfaces) by, for example, capillary action, and then the temperature is lowered and the material is solidified. This results in the surface-to-surface joining portion 61 and the surface-to-be-joined portion 30b being brazed together.

[0080] Of the reinforcing portion 6 assembled to the inner circumferential side of the coil portion 3 as described above, the portions facing the first slit hole 31 and the second slit hole 32 of the coil portion 3 can be accessed through the first slit hole 31 and the second slit hole 32, respectively.

[0081] For example, when the radially inner side of the second slit hole 32 is viewed from the outside, it is also possible to observe the surface joint portion 61 and the groove portion 62 of the reinforcing portion 6 as shown in FIG. 8(A) described later.

[0082] <Verification example> Next, a plurality of electrodes 2 were produced based on the embodiment, and the assemblability (brazing ability) of both the coil portion 3 and the reinforcing portion 6 was evaluated by the method described below. As comparative examples, a plurality of electrodes 9 shown in Figs. 8 and 9 were also produced, and similar assemblability evaluation was performed on each of them, as with the electrode 2.

[0083] First, the six second slit holes 32 formed in the coil portion 3 of each electrode 2 were observed from the outside to the inside in the radial direction. As a result, it was observed that fillets 70 made of the brazing material 7 were formed in almost all of the second slit holes 32 of each electrode 2, as shown in Fig. 7(A). In addition, when both the coil portion 3 and the reinforcing portion 6 of each electrode 2 were cut along the axis 35 and the space between the surface joining portion 61 and the surface joining portion 30b was observed through the cut surface, it was confirmed that the brazing material 7 had permeated widely between the two, and that the brazing had been performed as desired.

[0084] On the other hand, when each electrode 9 was observed through each second slit hole 32 in the same manner as in the case of electrode 2, it was found that a small fillet 70 was formed by the brazing material 7 only in a part of each second slit hole 32 as shown in Fig. 7(B), but the fillet 70 could not be observed in most of the second slit holes 32. In addition, when both the coil portion 3 and the reinforcing portion 6 of each electrode 9 were cut along the axis 35 and the area between the surface joint portion 94 and the surface jointed portion 30b was observed through the cut surface, it was confirmed that the brazing was insufficient compared to the case of electrode 2.

[0085] Therefore, according to the embodiment, it was found that the electrode 2 can be produced by brazing both the coil portion 3 and the reinforcing portion 6 as desired, and desired electrode characteristics can be easily obtained.

[0086] Although the present invention has been described in detail above only with respect to the specific examples, it will be apparent to those skilled in the art that various modifications are possible within the scope of the technical concept of the present invention, and it is natural that such modifications fall within the scope of the claims. [Explanation of symbols]

[0087] 1A…Vacuum interrupter 2a...Fixed electrode, fixed side current-carrying shaft 12a 2b...Movable electrode, movable side current-carrying shaft 12b 3...coil portion, 30a...inner wall surface, 30b...surface joining portion, 31...first slit hole, 32...second slit hole, 36...slit groove 4…Contact part 5...Adapter part, 6...reinforcement portion, 61...surface joint portion, 62...groove portion, 63...groove inner wall surface, 64...surplus space 7...brazing material, 71...notch

Claims

1. A vacuum vessel having an insulating cylindrical body; a pair of electrodes disposed in the vacuum vessel so as to face each other in an axial direction of the cylindrical body and to be movable toward and away from each other; a pair of current-carrying shafts supporting the electrodes on opposite sides of the opposing direction; Equipped with Each of the electrodes is A cylindrical coil portion extending in the axial direction; a contact portion provided at an opening in the opposing direction of the coil portion; an adapter portion provided on the opposite side of the coil portion in the opposing direction and supported by the current-carrying shaft; A reinforcing portion having a cylindrical shape with a smaller diameter than the coil portion and arranged concentrically on the inner periphery side of the coil portion; having The coil portion has a plurality of slit holes formed at predetermined intervals in a circumferential direction of the coil portion, the slit holes passing through the coil portion in a radial direction and extending in the axial direction, The reinforcing portion is a surface-joining portion that is surface-joined to an inner circumferential surface of the coil portion at an outer circumferential surface of the reinforcing portion; an annular groove portion extending in the circumferential direction in the surface joint portion; having the groove portion is open only on a side facing an inner circumferential surface of the coil portion, A vacuum interrupter, characterized in that the surface joint portion is brazed to an inner peripheral surface of the coil portion via a brazing material provided in the groove portion.

2. 2. The vacuum interrupter according to claim 1, wherein the surface joint portion is annular and expands in diameter from an outer circumferential surface of the reinforcing portion outward in the radial direction.

3. The brazing material is a filament extending along the groove, 2. The vacuum interrupter according to claim 1, wherein one or more of said filaments are provided for each of said grooves.

4. 4. The vacuum interrupter according to claim 3, wherein the number of stages of the filament provided in the groove in the axial direction is N, the number of stages of the filament provided in the groove in the radial direction is S, a wire diameter of the filament is φ, a dimension of the groove in the axial direction is w1, and a dimension of the groove in the radial direction is w2, satisfying the following formulas (1) and (2): φN<w1<φ(N+1)...(1) φS<w2<φ(S+1)...(2).

5. 4. The vacuum interrupter according to claim 3, characterized in that the filament has a cutout portion formed in a part of the circumferential direction that penetrates in the axial direction, and the cutout portion is elastically deformable so as to expand and contract in the circumferential direction.

6. A method for manufacturing a vacuum interrupter according to any one of claims 1 to 5, comprising the steps of: a brazing material placement step of placing the brazing material in the groove portion; a reinforcing portion assembling step of providing the reinforcing portion on an inner circumferential side of the coil portion and assembling the reinforcing portion; a melting step of heating and melting the brazing material; 13. A method for manufacturing a vacuum interrupter comprising the steps of:

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